Abstract |
Toxic Air Pollutants (TAPs) exhibit considerable spatial and temporal variability across urban areas. Therefore, the ability of chemical transport models (CTMs), e.g., Community Multi-scale Air Quality (CMAQ), to reproduce the spatial and temporal variability is needed to perform accurate exposure assessments and to be able to identify and characterize toxic hot spots, which are the areas that experience high levels of air toxics (AT). These areas are not only impacted by local sources but also by the secondary production of many air toxics compounds due to photochemistry and long range transport. For example, formaldehyde and acetaldehyde have secondary components of oxidant photochemistry. The source distribution, photochemistry, dry and wet deposition of these compounds are scale dependent. Therefore, in order to capture the spatial and temporal variability of these compounds and identify air toxic hot spots, it is necessary to perform air quality simulations at fine scales. |